Sealing arrangement for a displaceable device

ABSTRACT

A device, which is displaceable by pumping through a conduit and which is utilized to obtain the drive of tools introduced by pumping into a producing petroleum well, generally comprising an elastic sleeve externally provided with small plates which make contact with the inner wall of the conduit; the plates are annularly distributed around the elastic sleeve. Adjacent plates and the interlocking means, which provides a slight sliding play, reduce the hydraulic leakages between the plates when the latter are in a spaced position.

United States Patent Inventor Jacques Garnier LeChesnay, France Appl. No 831,471 Filed June 9, 1969 Patented June 8, I971 Assignee lnstitut Francais Du Petrole, Des

Carburants Ruell Malmaison (Hauts de Seine), France Priority June 7, 1968 France 154,118

SEALING ARRANGEMENT FOR A DISPLACEABLE DEVICE 5 Claims, 13 Drawing Figs.

US. Cl 92/182, 92/193, 92/252, 92/256 Int. Cl. F16] 1/06, F16] 9/08, F16j 9/14 Field 01 Search 92/250,

[56] References Cited UNITED STATES PATENTS 1,284,341 11/1918 l -lonegger 92/252X 1,518,801 12/1924 McArthur 92/193X 2,468,980 5/1949 Huber 92/182 FOREIGN PATENTS 590,380 4/1959 ltaly 2/Z l Primary ExaminerAl1an D. Herrmann Attorney-Craig, Antonelli, Stewart and Hill PATENTEDJUN 8l97i 3583292 SHEET 1 OF 3 JACQUES GAKNIER FIG. Id

BY div H ATTORNEYS PATENTED JUN 8197! mcaue 5 GARNIR ATTORNEYS PATENTEI] JUN 8197! 3,583,292

SHEET 3 OF 3 McauES u/m/vmm BY V Jaw; 4 1M1.

ATTORNEYS SEAUNG ARRANGEMENT FOR A DISPLACEABLE DEVICE BACKGROUND OF THE INVENTION The present invention relates to a device which is displaceable or movable by pumping through a conduit, and more particularly, a device which is usable for obtaining the drive of operating tools being introduced by pumping into a petroleum well in production, this introduction being made by means ofa conduit for the discharge of the production fluid by pressing back or ramming these tools into the well with the fluid.

The drive means known heretofore and utilized for this purpose consist generally of one member constituting a piston adapted to be fitted to one end of the tool to be introduced into the petroleum well and upon which acts the ramming pressure of the production fluid toward the well, thereby achieving a certain fluidtightness between this member and the wall of the conduit in which the operating tool and its driving means circulate.

This fluidtightness is generally obtained by inflating, under the action of the pressure of the rammed or compressed fluid, an elastic sleeve made from synthetic rubber which withstands the production fluid consisting, most frequently, of the degassed crude oil. However, this rubber sleeve must be protected against contact with the wall of the conduit in order to prevent very considerable wear and tear thereof, which, in turn, would put the driving device rapidly out of operation.

In the past, this protection has been obtained in practice by either lining the rubber sleeve or by covering the rubber with small metal plates. In the first instance, the fluidtightness obtained is very good, but the sleeves deteriorate rapidly. In the second instance, the driving means lasts longer, thus they are technically safer and more economical. But the fluidtightness which is achieved is not as good as in the first instance. Further, the driving means equipped with small metal plates used to date have a certain number of drawbacks which will be discussed hereinbelow.

The small plates are, in fact, cylindrical sectors externally lining the elastic sleeve and machined with the same external radius of curvature R, which is chosen to be equal to the mean inner radius of the conduit in which the driving means must circulate. When the device passes into a straight conduit having an inner radius equal to the radius R,,, the fluidtightness obtained is quite good with leakages occurring only through the free space left between the adjacent small plates so as to allow these small plates to be brought closer together when the diameter of the conduit decreases.

When, however, the inner radius of the conduit is greater than R,,, the distance between or spacing of the small plates being applied against the inner wall of the conduit by inflating the sleeve is increased and their surface of contact with the inner wall of the conduit is reduced. Consequently, the fluidtightness is not as good.

When, on the other hand, the inner radius of the conduit becomes smaller than R,,, the spacing of or distance between the small plates decreases and these small plates can draw close enough together so as to touch, but they bear on the inner surface of the conduit only at their ends, which still results in a poor fluidtightness characteristic.

The disadvantages and drawbacks outlined above are further increased when the conduit is curved, e.g. in the vicinity of the point of connection thereof with a production conduit or tubing of the petroleum well, and when the driving device passes into portions of the conduit whose cross section has somewhat oval shape, the existence of which is unavoida ble in the manufacture thereof.

SUMMARY OF THE INVENTION Accordingly, it is the aim of the present invention to provide a driving means of the aforementioned type which comprises an elastic sleeve equipped externally with small plates which make contact with the inner wall of the conduit in which it circulates.

The driving means of the present invention avoids the disadvantages and drawbacks of the prior art devices mentioned above and makes it possible to insure a good fluidtightness of the device with the inner wall of the conduit for different values of the inner diameter and the different shapes of the inner wall of the conduit which the driving means will encounter in the course of its displacement within the conduit.

The device of the present invention which accomplishes these objects comprises an elastic sleeve carrying or being provided with small plates which make contact with the wall of the conduit within which it circulates. These plates'have an annular distribution around the elastic sleeve. The device is further characterized in that the adjacent plates are equipped with male connecting elements or tenons such as projections and with female elements constituting at least one fitting or interlocking pair of these plates. This interlocking action or fit is produced with a slight sliding play; the tenons have a shape which essentially assume contour of the inner wall of the com duit in such a manner so as to maintain a substantially continuous contact of the plates with this inner wall even in a position where these plates have spacing therebetween. The combination of this contact and of the slight sliding play of the tenons or projections reduces the hydraulic leakage between the plates in this position of mutual spacing thereof. The device is further provided with stops or abutments preventing the dislocation or disconnection of the plates and also limits the distance of the plates with respect to the axis of the elastic sleeve as a result of the radial expansion thereof.

It is another object of the present invention to reduce the forces of reaction of the inner wall of the conduit at the supporting points of the device against this wall in which the incurvated or curvilinear parts of the conduit. This object is obtained by distributing or subdividing the plates into several separate contiguous rings surrounding the elastic sleeve and by disposing therebetween at least one stop wall for limiting the hydraulic leakages in a spaced position of the plates. This allows for a relative displacement of the rings in a transverse direction by a relative gliding of the rings on the contact planes of their extremities. Thus, the passage of the device in the incurvated portions of the conduit is facilitated by virtue of a reduction of the value of the reaction forces being exerted by the inner wall of the conduit at the supporting points of the device against this wall, with this reduction becoming more pronounced as the number of rings becomes greater.

According to an embodiment of the present invention which accomplishes this desired result, the device comprises at least two distinct rings of plates that are adapted to be closely applied against each other by means of the pressure of the fluid, with an alternate disposition of the plates of one ring with respect to the other rings in such a manner so that the space between the plates of one ring is essentially closed or sealed by a wall of the plate carried by or mounted on the other ring.

The application of the small plates to the inner wall of the conduit may be accomplished in a manner known per se by inflating the sleeve with the action of the pressure of the fluid being compressed in the conduit.

According to a preferred embodiment of the present invention, the radius of the outer surface of the manufactured elastic sleeve and the position of the stops or abutments are fixed in such a manner so as to limit the distance of the inner wall of the plates with respect to the axis of the ring to a value, at most, equal to the radius of the outer surface of the sleeve. This corresponds to a distance between the outer wall of the plates and the axis of the ring which is greater than the maximum radius of the conduit into which the device is introduced, which thereby produces a strong application pressure of the plates against the inner wall of the conduit by virtue of the radial precompression of the elastic sleeve through a reduction in the diameter thereof when it has been introducted by force into the conduit in the course of operation.

BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention, which is not limited thereto, and wherein:

FIG. 1 illustrates schematically one embodiment of the device comprising three rings of contact plates inside a rectilinear conduit;

FIGS. Ia, lb, and 10 are cross-sectional views taken along line -0 of the device as shown in FIG. 1, illustrating the variations in the spacing of the contact plates as a function of the variations in diameter of the conduit in which the device circulates;

FIG. id is a detailed view, also taken along the line (1-0 of, however, another embodiment of the present invention;

FIG. 2 illustrates the passage of the device according to FIG. I in an incurvated or curvilinear conduit;

FIG. 3 is an axial cross-sectional view on an enlarged scale of one embodiment of the present invention;

FIGS. 4, 5, 6 and 7 show the radial displacements of the contact plates as a function of the variations of the diameter of the conduit;

FIG. 8 is an axial cross-sectional view of another embodiment ofthe device according to the present invention; and

FIG. 9 illustrates still another embodiment of the device according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 illustrate schematically one embodiment of the device according to the present invention which comprises three rings 1, 2, and 3. The number of rings used in FIGS. I and 2 is merely illustrative because the device may comprise equally as well only a single ring. Preferably, however, a plurality of rings is employed, e.g. six in the device illustrated in FIG. 8, so as to improve or increase the contact with the inner wall of the conduit in which the device circulates when the conduit is incurvated as shown in FIG. 2.

As illustrated in FIG. 3, the device is provided on at least one of the ends thereof with connecting means such as threads 4 so as to connect the device to the tool so as to insure the drive thereof in the conduit 5.

As shown in FIGS. i, la, lb and 1c, each ring surrounding a sleeve 6 of elastic material, such as an elastomer, consists of an interlocking or telescopically arranged, or a slide-type group or unit of small metallic plates in contact with the inner wall of the conduit 5, having the shape of cylindrical portions. Each small plate comprises a male element consisting of a tenon or a hydraulic fluidtightness slide 8 and a female element or a housing 9 adapted to receive the tenon of an adjacent plate with a small amount of sliding play, which renders it possible to space the plates from each other or bring them closer together with respect to each other as a function of the variation of the inner diameter of the conduit 5.

Furthermore, as shown in FIGS. 1 and In, each tenon has, in cross section perpendicularly to the axis of the ring, a contour conforming essentially to that of the ring and consequently, to that of the inner wall 50 of the conduit in such a manner so as to maintain a contact with this wall between the adjacent plates on the ring in the spaced position of these plates, the tenon or male element thus forming a stop wall between adjacent plates.

The combination of this contact of the tenon with the inner wall 50 and of the small sliding play of the tenons 3 in the housing cavities 9 reduces the hydraulic leakages between the plates in the spaced positions thereof as shown in FIG. lb as compared to the previously proposed drive means wherein the plates are not connected with each other or are linked by means of a slight articulation which will in no way assure a secure and satisfactory fluidtightness. Here the tenons 8 constitute the stopping wall for the outflow of the fluid between the plates.

In the embodiments illustrated in FIGS. 3 and 8, the rings are disposed around a tubular mandrel 10 adapted to be connected to the tool so as to be driven in a conduit 5 and may comprise conventional end stoppers or calibrated discharge valves (not shown) in order to maintain a difference in the fluid pressure, respectively, upstream and downstream of the driving device.

The mandrel 10 is surrounded by or enclosed with the elastic sleeve made from an elastomer in which there are disposed, according to the embodiments disclosed herein, radially disposed extensions 11 of the plate 7. This sleeve is connected or glued by means of vulcanization on to the plates 7 and the radial extensions thereof.

Stops or abutments 12, 12a and 13, 130, respectively, carried by or provided on the plates 7 of each ring and by the mandrel 10 or by the plates of the adjacent ring, as shown in FIGS. 3 and 8, prevent the disconnection or dislocation of the tenons 8 illustrated in FIG. 1 by limiting the distance or separation of the plates 7 with respect to the axis of the mandrel.

In the embodiment shown in FIG. 3, crosspieces l4 assure the correct spacing between the rings or bands 15 being provided with the stops or abutments 13.

According to the modified embodiment as shown in FIG. lld, the radial portions llof the contact plates are connected by means of prestressed springs 18 for spacing the plates and the force thereof is in addition to that of the prestressed elastomer sleeve 6. The application of the plates 7 against the inner wall 5a of the conduit 5 may also be achieved, if desired, in a manner known per se by inflating the elastic sleeve 6 through the ramming or driving pressure of the fluid.

As shown in FIG. Ed, the sleeve may comprise hollowed-out portions or undulations 26 in order to allow for the flow of the elastic material at the moment of the radial compression of the sleeve.

However, according to a preferred embodiment of the present invention which is illustrated in FIGS. 45 to 7, the outer manufacturing diameter of the elastic sleeve 6 and the position of the stops or abutments112 and 13 are fixed in such a manner so as to limit the distance of the inner surface 7a of the plates with respect to the axis of the sleeve as shown in FIG. 7 to a value, at most, equal to the radius of the outer surface of the manufactured sleeve. This corresponds to a distance R between the outer wall 7b of the plates and the axis ofthe ring which is greater than the maximum inner radius R, of the conduit in which the device must circulate, as shown in FIG. 6, which, in turn, beings about a strong application pressure of the plates 7 against the inner wall 5a of the conduit 5 through the effect of radial compression of the elastic sleeve due to the reduction in the diameter thereof while in operation.

This preferred embodiment of the present invention is obtained by placing the plates into a mold having a cylindrical bore with a diameter greater than the maximum inner diameter of the conduit in which .the driving device must circulate and into which the elastic material, such as an elastomer which will comprise sleeve 6, is poured. The plates are connected, if desired, by means of springs that are maintained in a precompressed condition by the mold in which the casting or molding of the elastic material takes place. Therefore, since the diameter of the sleeve 6 when in operation is reduced with respect to the diameter thereof before being used, the plates 7 are applied against the inner wall 50 of the conduit 5 chiefly by the effect of the compression of the elastomer to which is added, if desired, the effect of the precompression of the springs l8, if such are present. In the preferred embodiment, the stress of the application of the plates against the inner wall of the conduit is thus brought about chiefly by means of precompression, while the inflation of the sleeve due to the ef feet or action of the production fluid pressure is employed only accessorially and may even be virtually eliminated if this production fluid is allowed to exert its pressure at the same time upon the outer wall and upon the inner wall of the sleeve 6 (orifices 16 as shown in FIGS. 3 and 8).

It is also possible, if desired, to dispose orifices 16 i'nthe tubular mandrel-l as well as orifices 17 in the annular crosspieces 14 as shown in FIG. 3, so that the pressure of the fluid acting on the inner and outer walls of the elastic sleeve is balanced. The plates 7 are then applied against the inner wall a of the conduit 5 solely by the radial precompression of the sleeve 6. Thus, the risk of the plates 7 being separated or detached from the wall 5a due to possible excess of the fluid pressure on the outer surface 7b of the plates with respect to the pressure which this fluid exerts upon the inner wallof the plates through the elastomer is eliminated.

FIG. 9 illustrates still another embodiment of the present invention which includes distributing or subdividing the contact plates in at least two rings (three rings 19, 2 0 and 21 are illustrated in FIG. 9) with an alternate or staggered arrangement of the plates from one ring to the other. When, under these condition, the rings are applied closely against each other by the pressure of the fluid, a wall such as 22 of one plate pertaining to one ring such as 19 constitutes a stop wall for the outflow of the fluid through the free space 23 remaining between two adjacent plates 24 and 25 of the adjacent ring 20.

It is understood that the present invention is not limited to the embodiments shown and described herein but encompasses any variations thereof. For example, it is possible to provide an interlocking action or connection of the tenons within the female portions of the plates which is of the type which glides in grooves, and/or terminal or top-end stops or abutments of the tenons cooperating in turn with corresponding stops or abutments of the female cavities or recesses in which these tenons are engaged.

It is equally possible to utilize adjacent plates of two different types, one of these types comprising at the two ends thereof male interlocking or jointing elements, and the other type comprising female elements, the two types being alternated over the circumference of the elastic sleeve.

In all of the cases that are feasible, it is possible for purposes of safety in operation to provide for a control relative to the wear and tear of the metallic plates by arranging small circular channels on the cylindrical portions being in contact with the conduit. The depth of these channels is to be determined or will depend upon the amount of safety desired. The disappearance of these channels as a result of wear and tear of the metallic surfaces in contact with the conduit during the circulation of the tool furnishes an indication which permits a decision to be made as to the eventual replacement of the tool. I, therefore, do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as encompassed by the scope of the invention.

What I claim is:

l. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variations in the diameter of the inner wall of the conduit, and wherein the body includes an elastic sleeve provided with hollowed-out portions between adjacent plates of a ring, in order to allow for the flow of the elastic material during a radial compression of the sleeve.

2. A device being displaceable by pumping through a conduit, comprisin a body, plates being carried by the body and adapted'to, ma e contact with the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variations in the diameter of the inner wall of the conduit, the body being tubular and including an elastic sleeve, at least one stopwall being'provided between adjacent plates thereby limiting hydraulic leakages when the plates are in a spaced position, the elastic sleeve carrying the plates maintaining a distance between the axis of the tubular body and the outer wall of the plates adapted to contact the inner wall of the conduit, before the use thereof in the conduit the distance being of greater value than the maximum inner radius of the conduit within which the device must be introduced, and wherein the body is provided with stops or abutments cooperating with corresponding stops integral with the plates and limiting the distance of the plates with respect to the axis of the body.

3. A device according to claim 2, wherein the adjacent plates are operatively connected with each other by spring means embedded in the elastic sleeve.

4. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variation in diameter of the inner wall of the conduit, at least two distinct rings of plates being provided contiguous to each other by means of the end faces of the rings which are adapted to be pressed closely against each other by fluid driving pressure, and wherein the radial displacement of the plates of a ring with respect to the plates of the contiguous ring is limited by stops carried respectively by the plates of each ring.

5. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, each plate covering only a sector of the cross section of the body, the plates being annularly distributed around the body and adapted tobe spac'ed therefrom so that the plates can be pressed against the inner wall and the body, following the variations in the diameter of the inner wall of the conduit at least two distinct rings of plates forming a first and a second ring contiguous to each other by means of the end faces of the rings which are adapted to be pressed closely against each other by fluid driving pressure and the plates of the first ring being staggered with respect to the plates of the second ring so as to substantially close the space between the plates of the first ring by means of a wall of a plate carried by the second ring. 

1. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variations in the diameter of the inner wall of the conduit, and wherein the body includes an elastic sleeve provided with hollowed-out portions between adjacent plates of a ring, in order to allow for the flow of the elastic material during a radial compression of the sleeve.
 2. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variations in the diameter of the inner wall of the conduit, the body being tubular and including an elastic sleeve, at least one stop wall being provided between adjacent plates thereby limiting hydraulic leakages when the plates are in a spaced position, the elastic sleeve carrying the plates maintaining a distance between the axis of the tubular body and the outer wall of the plates adapted to contact the inner wall of the conduit, before the use thereof in the conduit the distance being of greater value than the maximum inner radius of the conduit within which the device must be introduced, and wherein the body is provided with stops or abutments cooperating with corresponding stops integral with the plates and limiting the distance of the plates with respect to the axis of the body.
 3. A device according to claim 2, wherein the adjacent plates are operatively connected with each other by spring means embedded in the elastic sleeve.
 4. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact With the inner wall of the conduit, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, wherein the body consists of at least one ring, and the adjacent plates of the body are equipped with male and female complementary connecting elements which constitute at least one interlocking pair of adjacent plates, the connecting elements being adapted to glide within each other with a small amount of play therebetween so as to allow a relative displacement of the adjacent plates and thereby vary the spacing thereof in accordance with the variation in diameter of the inner wall of the conduit, at least two distinct rings of plates being provided contiguous to each other by means of the end faces of the rings which are adapted to be pressed closely against each other by fluid driving pressure, and wherein the radial displacement of the plates of a ring with respect to the plates of the contiguous ring is limited by stops carried respectively by the plates of each ring.
 5. A device being displaceable by pumping through a conduit, comprising a body, plates being carried by the body and adapted to make contact with the inner wall of the conduit, each plate covering only a sector of the cross section of the body, the plates being annularly distributed around the body and adapted to be spaced therefrom so that the plates can be pressed against the inner wall and the body, following the variations in the diameter of the inner wall of the conduit at least two distinct rings of plates forming a first and a second ring contiguous to each other by means of the end faces of the rings which are adapted to be pressed closely against each other by fluid driving pressure and the plates of the first ring being staggered with respect to the plates of the second ring so as to substantially close the space between the plates of the first ring by means of a wall of a plate carried by the second ring. 